The optimal reaction conditions for the synthesis of nylon-6,6 from adipic acid and hexamethylenediamine to maximize yield and minimize side reactions are as follows:1. Molar ratio: To ensure maximum yield, the molar ratio of adipic acid to hexamethylenediamine should be 1:1. This stoichiometric ratio allows for the complete reaction of both reactants, minimizing the formation of side products.2. Temperature: The reaction is typically carried out at elevated temperatures, in the range of 200-300C 392-572F . Higher temperatures promote the formation of the amide bond between adipic acid and hexamethylenediamine, increasing the reaction rate and yield. However, temperatures above 300C may lead to degradation of the nylon-6,6 polymer and the formation of undesirable side products.3. Pressure: The reaction is often performed under reduced pressure around 1-5 mmHg to facilitate the removal of water, which is a byproduct of the reaction. Removing water from the reaction mixture helps drive the equilibrium towards the formation of nylon-6,6 and minimizes the occurrence of side reactions.4. Catalyst: The use of a catalyst, such as acetic acid, can help increase the reaction rate and improve the yield of nylon-6,6. The catalyst should be used in a small amount around 0.1-1% by weight to avoid any negative effects on the polymer properties.By carefully controlling these reaction conditions, it is possible to maximize the yield of nylon-6,6 and minimize the formation of side products.